Santiago Ramon y Cajal

If I am going to talk about how beautiful neuroscience can be, I should probably mention, fairly early on, the most famous neuro-artist there is. 

Take a minute to compare the two images below. Both are of a type of cell called a Purkinje cell, which are found in the cerebellum (at the back of the brain), and are essential for normal movement. One was draw, hand drawn, using paper and ink, in 1899. And the other, no less miraculous, was imaged using all the most sophisticated techniques we have at our disposal these days, by creating mice that express each neuron in the nervous system as a distinct colour, and imaging the brain using confocal microscopy. These 'brainbow mice', are quite brilliant, and are a story for another day. Today I want to focus on the scientist who managed to draw the same structures, in perfect anatomical detail, 108 years before the brainbow mice existed. 

Purkinje cells (labelled 'A') from the cerebellum of a pigeon, drawn by Cajal in 1899. Instituto Santiago Ramon y Cajal, Madrid, Spain.

Purkinje cells from the cerebellum of a mouse, imaged by Tamily Weissman in 2007. From the Brainbow mouse, produced by Livet J, Weissman TA, Kang H, Draft RW, Lu J, Bennis RA, Sanes JR, Lichtman, JW. Nature (2007) 450:56–62. Image can be found here.

His name was Santiago Ramon y Cajal, which is fun to say, and he was born in a village in north-east Spain in 1852, the son of the village surgeon. According to history, Cajal wanted to be an artist, but his father insisted he went to medical school instead. So he continued with art, but with anatomy as his subject. He saved up to buy himself an old fashioned microscope to begin his studies (I mean, now it would obviously be old fashioned, but apparently this one was old even in 1877), and was enventually awarded a shiney new one for the work he did during a cholera epidemic. 

In 1887 he was shown some slides of tissue stained with a new technique developed by an Italian scientist called Camillo Golgi. Golgi's techinque involved impregnating tissue with silver, which stained individual cells black and showed them with much greater clarity that the methods that Cajal had previously been using. Cajal wrote in his autobiography that "all was sharp as a sketch with Chinese ink". He modified this technique, and used it to provide the foundation of modern neuroanatomy, drawing thousand of beautiful images showing the intricacies of the nervous system in several species. Based on his observations he also came up with the theory that our brains and spinal cords are made up of countless individual cells, none of which come into direct contact with each other. These cells were later named neurons.

In 1906 Cajal and Golgi were jointly awarded the Nobel Prize in Physiology and Medicine for "revealing the inner beauty of the nervous system", becoming the first scientists ever to share the prize. This was slightly awkward, because Golgi had an conflicting opinion of the nervous system, believing it to be made up of a single continuous mesh. Apparently, their Nobel lectures directly contradicted each other. With the development of more powerful microscopes it was eventually possible to actually see a gap between cells in the nervous system, and Cajal was proved correct.

Laura